You may be able to,Jvt,but I've never heard of doing so..I think you are better just using seed compost,especially for the purpose..it's low in nutrients and more gritty,and when they are growing well.. pot on into multi compost..someone else may beg to differ..

Too rich by miles, especially nitrogen. Seeds need low nutrient levels when they first germinate so I concur - get JI seed compost.
Worm compost is great as a mulch/top dressing for hungry plants in pots.

So grateful for the advice, many thanks. John

You're welcome John..:o)